From the standby server, a health check I/O is issued asynchronously with an I/O operation performed by the user, and therefore an I/O from the server might continue on a volume on the storage system connected to the standby server if a remote path failure occurs. This might cause an unintended failover.
When I/O preference mode when remote path failed is set, an I/O from the server can continue on a P-VOL and the operations can be performed on the P-VOL if a remote path failure occurs, which prevents an unintended failover.
CAUTION:
When I/O preference mode when remote path failed is set to Primary Volume, if a failure that prevents an access to a P-VOL (for example, a path failure from the server to the P-VOL) occurs at the same time, the access might be lost.